The present disclosure relates to an imaging apparatus and an imaging method for capturing a three-dimensional image.
In recent years, an imaging apparatus that uses a stereo image captured from two different positions to calculate a position of a subject in a three-dimensional space and generate a three-dimensional image has been known. Such an imaging apparatus is used for three-dimensional object recognition in manufacturing facilities for industrial purposes or widely used as a system allowing stereoscopic viewing for broadcasting or domestic use.
In such an imaging apparatus, a color filter of R (red), G (green), and B (blue) is arranged in front of a light-receiving surface of an imaging device. The color filter allows light entering the light-receiving surface of the imaging device to be split into light of wavelength components of the respective colors R, G, and B, so that a color image using image signals of the decomposed R, G, and B is generated by the imaging apparatus.
However, the light entering the light-receiving surface of the imaging device through the lens is attenuated by passing through the color filter, and thus the amount of light entering the imaging device is also reduced by an amount corresponding to the attenuation. In other words, the sensitivity of the imaging device is reduced. Further, along with the achievement in high definition of images in recent years, the pixel size is reduced and the sensitivity is also reduced accordingly.
For that reason, in such an imaging apparatus that captures a color image, various techniques for improving the sensitivity of imaging are devised. For example, Japanese Patent Application Laid-open No. 2011-176710 discloses a technique in which a part of a color filter is replaced with a transparent filter to increase the amount of light taken in by an imaging device and improve the sensitivity.